CA12 28 Preparing for Future Eruptions Mt Saint Helens Carolyn Driedger

Communications Academy 2012

Preparing for Future Volcanic
Eruptions - Mt. St. Helens
Lessons Learned

Carolyn Driedger

U.S. Geological Survey,
Cascades Volcano Observatory
April 15, 2011

When Mount St. Helens erupted in May, 1980,
we made the most of it... ;

=>

IN J 4

a aes

Our sense of humor —

fn . x
‘

~
i

OF AMERICA

REO. US. PAL OFF.

Poe ne Lt ee ae ee eee

6 Cl it i,

...we adjusted...but what did we learn about their
effects upon our society? What part do emergency
communicators play during a volcanic eru

ption?

a ES awe Se say get oF eS

pee ee Pie a ase SN ean oie ee

=? * och CR EES he: ¢ me »
Bae Aes “ 4 “hes

ll ee
ad

_ The time to learn about volcanic eruptions
before we need to live with them...

d Caner

Contents of this talk

ide
zard

ation

Helens Mount St. Helens 1980 to Monitoring
present. Restless

Volcanoes

Evidence of active volcanism
Multiple hazards

Economic impacts
Recommendations for preparation.

Let’s take a closer look.
Mount St. Helens 1980

eLack of eruption pre-planning and
experience with large eruptions.

ePublic (and officials) unaware of eruption
potential in Cascades.

eEruption legacy in science, eruption
response, preparedness and recovery (pre-
dated coordinated inter-organizational
responses)

Timeline: Pre-May 18, 1980 Eruption

1978: USGS-MSH hazard
assessment; states eruption Is likely
within 100 years, “perhaps before the
end of the century”

3/20/80: First significant earthquakes
03/25: First exclusion zones

03/25: TFR in place

03/27: First ash explosion

04/03: State emergency declaration
05/17: Some cabin owners escorted
to Spirit Lake; others planned for 5/18
05/18: Eruption at 8:32 a.m.

USGS, 5/17/1980

Timeline: May 18, 1980

Eruption at 08:32 a.m.

¢ North flank landslide and lateral
blast devastate 600 km? (230 mi2)

¢ Eruption column to 20 km (12.5
mi) in <10 min

¢ Eruption lightning starts hundreds
of small forest fires

¢ Ash causes darkness to east for
>650 km (400 mi)

¢ Lahars extend ~ 130 km (80 mi)

Timeline: post May 18, 1980

5 smaller explosive events through
October 1980

Episodic ERUPTIONS! Lava dome
growth from October 1980 to October
1986

1989-1991: 22 seismic swarms and 6
ash explosions

Increased sedimentation in Toutle
River still an issue (2011)

USGS, 1980

Physical and Human Effects

9/7 fatalities —
About 200 homes destroyed by lahars _ ~~

Extensive damage to land and
infrastructure

—- devastation of 600 km2 of forest
- bridges, roads, railways

—- sewage disposal/water supply re usGel so *
- loss of Spirit Lake recreational
area

Ash severely affects southern
Washington to Montana

Economic Impacts

Estimate: (1980 $) — $1-2B
¢ $450M timber destroyed
¢ $40-100M agricultural damage
e >$100M infrastructure damage

e $1B- water transportation and
mitigation

e Ash cleanup costs—total unknown oe

ec
aZUSGS

Lessons Learned from 1980
events

Long-duration events quickly
deplete resources and patience

Recovery can be slow.

Public officials need to make
safety decisions before
outcomes are known

Interagency planning essential

Hazards persist long after a
large eruption ends

Volcano monitoring is critical

Progress in 30 years

USGS-CVO observatory established

Research about eruption potential at
OTHER Cascade volcanoes.

Interagency response plans created for
most WA and OR volcanoes

National Incident Management System -
a tested approach

A much more informed public

Challenge is more people living close to active volcanoes. The most recent
disaster fades from memory before the next strikes.

What happened after 1980?

1980-86: MSH eruption: eruption story spreads globally
1980s-2004: Update of monitoring, hazard assessment, and
coordination plans throughout Cascades, but especially at MSH
1989-1991: 22 earthquake episodes, 6 with explosions

2003-04: Quietest seismic period since 1980

2004 First Sign of Unrest: Earthquakes

9/23: earthquake swarm (similar past swarms did not result in eruption)
9/24-9/25: hundreds of earthquakes, then decline

9/24: release of Information Statement triggers call down, initiation of
meetings between federal, state and local officials

9/26: uptick in energy release prompts Notice of Volcanic Unrest

Alert Level Changes Draw Notice

Uptick in activity leads to major response; high uncertainty

9/27: media tsunami at CVO; high demand on scientists’ time
9/28: deformation of crater ice confirmed

9/29: 3 to 4 earthquakes per minute; alert level raised to Volcano Advisory
10/1: first steam and ash eruption; plume rose to ~12,000 feet

10/2: volcanic tremor prompts Notice of Volcanic Alert; Interior Secretary
Gayle Norton visits CVO

10/3: Joint Information Center opens
10/2-10/5: more steam eruptions thrill observers

An Eruption in Real Time
Explosion viewed by millions, Oct. 1,2004

Y: Ss
x =e —_Pa))

~~

“~ J

"< - —

October 4, 2004

2004-2008 Slow extrusion of lava
formed a ‘lava dome’

sof Mount St Helen os
~200/ 2006

Unified Command &
Joint Operations Center (JOC):

Joint Operations Center in operation
for two weeks.
Joint Information Center located
away from media crowds (800
requests in 11 days)
Cost USFS $95K

—- no declaration of emergency

meant no reimbursement to USFS
and local agencies

The Joint Information Center (JIC)
served many functions

¢ Media Monitoring
¢ Rumor control
¢ Tracking JIC messages

¢ News releases
¢ Talking points

¢ Source for media and ¢ JIC chronology

public inquiries

Activity Level vs. Public Interest

—_-_ —_- —_- —_—
(— an er
aoa nN ow
—

eUSFS webcam: 36
million hits 9/24 & 10/5
“USGS site: 55,000 to
1.43 million hits daily

eInternet capabilities of
both exceeded

Q
—
c
S
°
2
=
<x
7p)
oa
=
5
—)
—

salinbuj Jo spuesnoy| u
‘,Paysanbay seabed jeNplAIpuj,, }1SqaM OAD

1)
2)
3)
4)

me 5)

Five lessons to apply:

V
Cascade volcanoes are ‘active’ and functioning volcanoes
doing what volcanoes normally do.
Your volcano will erupt again. There will be a short period or
warning.
Multiple hazards and long-term uncertainties.

Economic impacts can last for decades.

There is demonstrated value in inter-agency preparation—
anticipating needs, developing and practicing response
plans, volcano monitoring, education.

_ Cascade volcanoes are active, functioning volcanoes.

Long periods of quiet punctuated by eruptions

EVIDENCE:
eActive hydrothermal
systems

eActive seismicity
(earthquakes)

eRecentness of eruptions ~ North
Zé erican
Plate

ZSVolcanoes « Earthquakes

eLocation at Cascadia
subduction zone with active
magma generation.

Modified from Yelin and others, 1994

Your volcano will erupt again

Eruptions in the Cascade Range During the Past 4,000 Years

Mount Baker

Glacier Peak

Mount Rainier

Mount St.Helens ~~~
Mount Adams

Mount Hood

Mount Jefferson

Three Sisters
Newberry Volcano
Crater Lake

Medicine Lake Volcano
Mount Shasta

Lassen Peak

California

2,000
Years Ago
Ee Eruption or period of multiple eruptions at or near named volcano

ll erupt again

Your volcano w

an

. h H
: 4 ’ - a . ,
“e : eis »~ re we re '
. owt . .
0 k - . - PP 3) :
. , . . ; 4 . ~~ wt
aa + we " ee t . . ses
= . : f - :
“ =o . . . *, 4 is < ,
- s + 7 t te ;
. { f .
: 1 “< ': ivér’> iA
4 a 1 ~4 i .
© - ¢ _ > t . ¢~ . j , ?
. 5 : ‘ . s >
. - ‘ - 7 °
' " 4 a er we fa - ‘ss :
: 4 i - * 4 SS! _
A 3 ; P 3 Ts ¥
. . Jers ome 4.
o ‘ .* >
a ) J /_ sae &
T> ml Ms 2 oo a ns
” 5
> ~

1

Be.

- : * a oe - , =

Your volcano will erupt again, but you will be
warned

As magma moves to the surface:

- lt breaks a pathway

¢ It releases gases

¢ The chamber or conduit may
increase or decrease in volume

These processes result in effects
that we can measure:

¢ Earthquakes

¢ Emission of magmatic gases,
principally CO, and S gases

¢ Ground deformation

Surface
deformation

Lava dome

Taleleime)i
magma

Seismicity

:

You will be warned

Tilt, Strain,

Temperature

Mudflows
Rainfall

Deformation

USGS mandate is to provide warning

USGS alert-level system focuses on the state of the volcano with an
emphasis on ash for the aviation community

Alert level Aviation Color Code

TERM DESCRIPTION COLOR DESCRIPTION

NORMAL Typical background, non-eruptive state

ADVISORY Elevated unrest above known
background activity

Heightened/escalating unrest with increased
potential for eruptive activity. timeframe
variable, OR, minor eruption underway

that poses limited hazards

Highly hazardous eruption underway
WARNING or imminent

USGS

You will be warned

IMAGES HAZARDS

Latest U.S. Volcano Alerts and Updates for Thursday, Oct 28, 2010 at 14:48:41 PDT“

Cieveland Advisory Yellow
Kilauea Watch Orange
Long Valley Volcanic Center Normal Green
Cascade Range Normal Green
Pagan Advisory Yellow
Sarigan Unassigned Unassigned
Anatahan Normal Green
Mauna Loa Normal Green
Yellowstone Normal Green
Explanation of alert levels and color codes

Features

Websites: http://volcanoes.usgs.gov

PUBLICATIONS

OBSERVATORIES

Scientific information:

e USGS and PNSN for
volcanic activity

eUSGS for warning - Alert
Level System

e USGS and NWS for ash fall
and lahar warnings

Response Information
e NIMS/ Unified Command

e Interagency response plans

Public information
e Media
e Social media

Warnings will not be B&W

The 1980s eruption was about 5 times larger
than the 2004 to 2008 eruption; largest MSH
event about 6 to 8 times larger than the
1980-86 event.

EMs will need to make decisions long
before outcomes are known

_- “Decision window”
for public officials

Shape, character,
duration very irregular

Build-up suggests
eruption is likely

Cannot guarantee that
eruption will not occur

Intensity of monitoring parameters

zuscs "OS

EMs will need to make decisions long
before outcomes are known

Decision
rs window for ehfier
5 Sas eG Eruption 3 p
7 officials
=
©
©
foe
oy)
<
9
(e
fe)
=
Oo
ran
€
® Serr Back to
(FS

sleep

Time —~
ZUSGS

~ Multiple Volcano hazards and
long-term uncertainties

Volcanic events can last for weeks, months, decades

Hazardous Warning Event Duration :
Event Weeks to Days Days Weeks to Months
months to years

months
Flood

Hurricane

Earthquake
/tsunami
Wildfire

Eruption

Multiple Volcano hazards

Proximal areas ( $15 mi) subject

: 55 i
to multiple lethal hazards: ee
Eruption Cloud

Eruption Column

: Tephra (Ash) Fall
Intermediate areas (> 15 <100) ae

Lahars, tephra fall and floods affect L
river valleys:

¢ Distal hazards (>100 mi) - Tephra
fall affects areas downwind:

Excess sediment in watersheds
reduces flood capacity:

Lahar hazards

¢Know which volcanoes are up valley of
your community.

eAsk scientists where the most likely vent
area will be and what rivers it might affect

¢Have a plan to deal with reservoirs on
potentially affected rivers

EXPLANATION
Ba Debris flow hazard zone

CJ Lahar hazard zone

Post-lahar sedimentation zone
in Green-Duwamish valley

- Cc] Lava flow and pyroclastic flow
hazard zone

| 0 5 10 Kilometers |

Lahar at Semuru volcano, Indonesia
Video by Franck LaVigne

Lahar hazards

Hazards can persist long after an eruption Is over

Fill tevel 2 yr after eruption

zeaaeSeye BR B

s
§
5
e
E
E
ww

Lahar hazards

Hazards can persist long after an eruption is over

Bridge crossing immediately
affected by the eruption;
months later

Some communities in the
Philippines were not affected until
years to a decade after the eruption

Volcanic Ash

e Particles of shattered
rock.

e Falls at normal air
temperature at
distance from the
volcano.

e Non poisonous to
touch or breathe.

e lrritates eyes,
breathing difficult,
reduces visibility,
abrasive, clogs filters.

Tephra (ash) hazards

MOUNT\(— 98509)
or eel —
‘ag

}
Portland

OREGON
IDAHO

300 KILOMETERS

200 MILES

Pdcatello :
_ 1816+

Figure 341.—Isochron and isomass maps compared. Black lines,
isomass of fallen-ash lobe: and red dashed lines,
trol. Time in PDT. See figures 332, 338, and text

isochrons of airborne-ash plume; red lines,
inferred positions of isomass lines extended beyond area of con-
for further explanation.

aZUSGS

: M4 ACOU Yor

Wes /%6

Radio, TV and Telephone
Communications...

...are extremely vulnerable to disruption
during volcanic ash fall and may fail
completely in eruption-effected areas.

However, there are many examples of

functional communication during ash fall.

ZUSGS

Impacts of Volcanic Ash on
Communications

e Disruption of signal during
eruptions

e Overloading of telephone/computer
communication systems.

e Disruption of electrical supplies

e Cooling systems challenged

e Electrical shorting of equipment
e Long-term abrasion of equipment

ZUSGS

Examples of Communication
System Overloads

e Overloaded Telephone
Systems
— Mount St. Helens 1980
— Mount Spurr Alaska 1953,
1992
— Mount Ruapehu NZ 1995-96

e Overloaded Internet
Systems
— Mount Ruapehu NZ 1995-96
— Nisqually Earthquake 2001

ZUSGS

Examples of Signal D1

e Katmai Alaska 1912—Radio
communications inoperative.

Surtsey, Iceland 1963—Clicks of radio
static common.

Pinatubo, Philippines 1991—
Disruption of radio and telephone
communications.

ZUSGS

Mitigation Measures
Communication Systems

¢ Seal facilities including Repeater Stations
— Shut air intakes

— Use internal air circulation
— Seal all equipment that is not already
watertight.

ZUSGS

Mitigation Measures
Communication Systems

¢ Remove Ash from external electrical
systems and from /insulators/antennae/

microwave dishes.

— Shut down electrical systems and vacuum, dust, and
blow ash from electrical equipment.

— Replace Teflon with ceramic insulators.

— Install covers; plastic tarps work well in emergency.

Mitigation Measures
Communication Systems

¢ Factors affecting electrical flashover 14

— Weather conditions (high air moisture
content increases ash adherence).

— Presence of electro-static charge.

— Grain size and ash fall thickness.

— Soluble components on ash
(conductivity).

— Insulator condition and orientation.

Mitigation Measures 4
Communication Systen<

e Further Cleanup

— Plastic switches abrade
quickly; Replace.

— Clean equipment daily with =-"a 3

compressed air or vacuum. ~~
— Keep moisture out of
Be as ecicidelog i

~
is

Mitigation Measures
Communication Systems

e Practical Advice
e Protect yourself and others.

e Recognize potential for ash fall
locally.

e Assemble items required for

sealing facilities and for

cleaning equipment.

Maintain backup electrical and

communication systems.

ZUSGS

Most serious issues

e Most serious problems result from the conductive
and abrasive properties of ash.

e Ash may be resuspended by human activity for
months after an eruption.

e Expect disruptions of signals, overloading of
telephone/computer communication systems, and of
electrical power, electrical shorting of equipment,
abrasion of equipment.

e Most effective measure is to reduce input of ash into
systems.

y

)

a USGS

Tephra (ash) hazards

Tephra affects aviation, which may impede recovery efforts

f}

ye

VA

fal

LATALC=

¢ ~2000 flights over the Cascades daily

¢e Ash can reach cruise altitudes in a matter
of minutes

How would reduced aviation affect your recovery?

Tephra (ash) hazards

Partners

Volcano H s Program Site

Tranporaion | Wate Sune | eter | Aslons | Cleans

What is Volcanic Ash? Volcanic ash brochures

Volcanic ash consists of tiny jagged pieces of | Two ash fall hazards pamplets published by the International Volcanic
rock and glass. Ash is hard, abrasive, mildly Health Hazard Network (IVHHN) are available on the IVHHN
corrosive, conducts electricity when wet,and Pamphlets webpage.
does not dissolve in water. Ash is spread over
broad areas by wind.
| Ash properties & ash distribution | GUIDELINES ON
THE HEALTH HAZARDS PREPAREDNESS
What Is it like during an ash fall? OF VOLCANIC ASH BEFORE, DURING AND
Falling ash can turn daylight into complete A guide for the public AFTER AN ASHFALL
darkness. Accompanied by rain and lightning, a [Ss
| the gritty ash can lead to power outages,
wy prevent communications, and disorient people.
Image as of 2 ]

bean for homes, businesses, & communities
Taking action before, during, and after an ash
fall can prevent or reduce many of the
damaging effects of ash. Removing ash requires
disposal sites and coordination among
individuals and households, community
organizations, and businesses.
| Actions to take | Ash clean-up | Volomnia ail i.
Managing ash fall in Yakima, Washington, from the 1980 eruption of Information relating ote — hazards of
Mount St. Helens: Overview by Dick Zais, City Manager gases and aerosols typically emitted during
volcanic activity are also available from the
International Volcanic Health Hazard Network
References and Web Links é : : ;
< Raleeesianl be Sas wide = wa (IVHHN).See introduction to volcanic gases

° International Volcanic Health Hazard Netw ork poker sedcettial pollation rr guidelines based on international urban and

http: rroleanece! usgs.gov/ash/

A distal volcano may affect you the most

Tephra (ash) can affect communities far from source

124°W

400 MILES
)

400 KILOMETERS & Mount Seager Annual

{inset map of Novarupta ash fall is at same scale,) ; a Mourt Cayley Probability |
& Mount Garibaldi > 10cm

Arey howl 2h-cantury erupt
ash fall thicker than about 0.2

Glacier Peak 4 ~ “4 ,

feast ciel eriphornes ¢ } y
a
Hereer. et) Gepomity, mist Pecks é hh , A Nout Baker

s Glacier Peak
A
Mt St Helens

YELLOWSTONE ASH
Crater Lake erupted 666,000 years agc
Mt Mazama)

MAZAMA ASH ee vellowstone
erupted 7,600 yearn, ayo Caldera Complex

~ a
4 Wocunt Jetierson
& Three Sisters
ray
Long
Valley

Caldera ; & Crater Lake
Anchorage e

Area al mag Mt Spurr,

A Newberry Volcano

ALASKA

BISHOP ASH
erupted 760,000 years ago

from Long Valley
"ACTE Novarupta """ A Medicine Lake Volcano
cs A ce 4 Woont Shasta

OCEAN .SH 191 ; Lassen Volcanic Carter

Economic Impacts can last for decades
Resuspension of volcanic ash, dredging sediment from lahars

ee
ath 5% Me - ae <A ~s sl
Oe e «s Uo wanes
GALL os

= fe
4 i is! WR.

le

lid

aUSGS

Eruption duration

Your volcano may be above or below average

Mount St. Helens, WA: 1980-86
Mount St. Helens: 2004-08

Eruption Duration
n=39%4

Kasatochi, AK 2008: 20 hours
Okmok, AK 2008: 3 weeks
Redoubt, AK: 1989-1990; 5 months
Crater Peak, AK: 1992, 3.5 months

<1 1-7 631 16 612 12 2-5 610 10:20 20

<—— ap ——> ¢- mows» <r ——_—_> Unzen Volcano, Japan: 1991-1994
Sourftriere Hills, Volcano, Montserrat:
1995 - present
Santa Maria Voclano, Guatemala:
1923 - present

Small eruptions can be disruptive

Even small explosive eruptions have had world-wide affects

E-15 eruption was small, but affected
4 millions in Europe

Lightning often

occurs during ash e

eruptions; canaffect = = = s— CS A gee

nearby power and ” aE

communications x ——

Naa

Re-suspension of ash affected Icelandic communities
for months afterwards

Small eruptions can be destructive

Hot rocks interacting with snow and ice can generate large lahars

23,000 people lost their lives hours
after a small eruption at Nevado del
Ruiz, Colombia in 1985

ere

Above: Nevado del Ruiz
Right: The town of Amero
after the about 1 month after
the catastropic eruption on
13 November 1985

Prepare now! Educate your
community.

¢ Get to know the hazards in your
community

¢ Know the interagency response plan
for your community

¢ Know what materials are available
for training your CERT team

¢ Include volcanoes in your multi-
hazard training

¢ Know how to inform your community
(learn, inquire, plan)

Bringing it home to your community

Are you affected by lahars? [Explanation | Volcano Hazard Zones
¢ Do you have a regional lava flow Mi Proximal hazard | for Western Washington
hazard? wi pane |_ and Northern Oregon
¢ Are you directly or indirectly affected [Dhtavastow nazar | eC Mount Baker
by volcanic events? recningeon tnd’ ee >

Northern Oregon

¢ How could ash affect your recovery
plans/ability to help a neighboring
jurisdiction?

ae - -
Glacier Peak
py Seattle

HESS
Ay Ss

i> Olympia ra Mount
: > Rainier

Mount St. Helens
r Mount
7 = cr Adams

oe

Mount Hood

Prepare!

yth Fo
Birch roe a > “& Nooksack River
“ . e
Bay Ny
Glacier

Ferndale Ke : PX .
‘ Be
| ‘, =

Bellingham ®

Zz -
Samish’ oks ‘

Bay < Lake
f J Shannon

Concrete

Whatcom

Baker
Lake

Skagit River
ae
elAnacortes S Ss 3 Hamilton
Burling

\ ‘ <=: | aa
a 20 % Glacier
“Swinomi ot Peak

Indian@ Mount Hazard
Res. ¢ -l\ r; 3) Vernon

Skagit . . . .
Oak : ork Stillazuamish Rive
ja Bay / Nn. For

http://volcanoes.usgs.gov/
publications/assessments.php

> COMBINE DEMOLITION!
y | EMOLI vi 13

DEPRV & RAMEM LUNE

Know your role in an eruption response.

At the JIC - MSH crisis October 2004

Participate in classes, drills. Celebrate the volcano in your
backyard!

Add volcano preparations to your CERT multi-hazard training materials

Lahar Warning Test

10 am, October 28", 2002

What:

* Test of the lahar warning procedures for the
Puyallup and Carbon River Valleys.

* Outdoor warning sirens will be activated and will
run three to five minutes.

* Local television and radio news stations may run
the Emergency Alert Signal (EAS) test.

* NOAA weather radios will be activated during this
test.

When:
10 a.m., Monday, October 28%, 2002.

Where:
Orting, Sumner, Puyallup, and Fife

Why:

* Test the alert call-down process.

* Check the sound coverage throughout the valley.
* Check the different alerting mechanisms.

* Remind valley residents of the need for sirens.

Questions? Please contact Pierce County
Emergency Management, 253-798-7470.

Bringing it home to your community
Messages USGS gives to the public

e Learn—Become knowledgeable about volcano
issues. Learn whether you live, work or go to
school in a volcano hazard zone.

e Inquire---Ask public officials how they advise you
to respond.

e Plan---For how you and your family will respond in
the event of any natural disaster.

Get to know the hazards in your community

Mount Baker

Birch

Lake
Whatcom

§ Lake
Shannon

10 Miles
Skagit r

Bay 20 Kilometers

Oak
Harbor

Simplified from Gardner and others, 1995, Potential Volcanic Hazards form Future Activity at Mount Baker, Washington, USGS Open-File Report 95-498

Get to know the hazards in your community

Glacier Peak

if
y Lake Shannon

Skagit River _3 Concrete
A

Hamilton
> eed

ie Granite Fels Gt C2
92 ‘\

Lake
| Stevens

Spada
Lake

Get to know the hazards in your community

Mount Rainier

Federal Wayf —_/ SEE MAP ON PAGE XXX FOR HAZARD ZONES TO THE NORTH AND THE WEST
a ee “a —~S

Auckleshoot Indian Res! ~*
Enumclaw SS
r \ ro Whiz. Greenwater h
o N
; |
4 1 * NM A} . A
& Wilkeson vd oa 7 {|
2" %,
Rive National \P

Randle Cowl
&

- Eo

Riffe Lake

Simplified from Hoblitt and others, 1998, Volcano Hazards from Mount Rainier, Washington, USGS Open-File Report 98-428

Get to know the hazards in your community

Mount Adams

a cf
r )
i 2

‘ Yakima
Indian

Regional
Lava Flow

Mount

St. Helens
Hazard
Zone

Swift * \ “Trout Glenwood”
Reservoir ~ Lake 7

ott and others, 1995, Volcano Hazards in the Mount Adams Region, Washington, USGS Open-File Report 95-492

Get to know the hazards in your community

Mount St. Helens

Toutleg?%

2 > \

f
Silver Lake t

oi §
anasas 152? 3

te
SS ee OP ea py

“Johnston Ridge
River

River 4 Af
Cougar
Rive,

: Reservoir
Yale
Lake

10 Mies

20 Kilometers

Get to know the hazards in your community

Mount Hood

Regional > )) Mount Adams
Lava Flow
Hazard Zone Carson

Cc
Washouga
Ca /

219

Sh Mount |
Mount Hood 7 Hood ~

Village ee oS i
C Rhododendron imperline
' Oe * 135)

Government

White RW"
Timothy ee
Lake

regon, USGS Ope n

Information transfer before
and during crisis

‘Tareday, D

MOUNT ST. HELENS UPDATE

Curveas stamns is Vebcue Advisory (Alert Level 2); aviation calor code ORANGE. Ge
w tates of senarcesty, low ene. mem anid volearac gases, and

erupbon, cheer
ve Wot cause terarcoue comditres sales of the
4 descend i teraction of het rock: now andice. Thess hitees

crater ame frethe
pose a neghaybie bi below the Sediment Retention Structure (
hen teodels, show that any ash Couds that

Potential ash hazards: Wind tivesaity tiem the Nat
twaed recta

Potential ash hazards to aviation: Under cv
y rats Cas travel 100
Hypothetical eruption of Mount St. Helens
Volume = 10 million cubic meters, Column height = 12 km
MMS (15km) forecast winds 00 hrs UTC 07 DEC 05 (16 hrs PST 06 DEC 05)

Recowt wbeswrvations; Clear ooricbhe science for a changing workd

ontinase at a rate of one aw

Mourn St. Holorrs
Legend
T Apo
A Mowt St. Helens

Modeled Tephra Thickn

Ashfall modelling program by A.W. Hurst, NZ-IGNS
Wind de OMA ARL

1)
2)
3)
4)

me 5)

Five lessons to apply:

V
Cascade volcanoes are ‘active’ and functioning volcanoes
doing what volcanoes normally do.
Your volcano will erupt again. There will be a short period or
warning.
Multiple hazards and long-term uncertainties.

Economic impacts can last for decades.

There is demonstrated value in inter-agency preparation—
anticipating needs, developing and practicing response
plans, volcano monitoring, education.

The goal of planning ts to prevent nature
processes from becoming human disaste

rs
. .
‘ "

4

a Ey |
Cascades Volcano Observatory
360-993-8973 www.vulcan.usgs.g

hd

’
i ¥